Quick change motor-mounted arbor mounting assembly and replaceable unit therefor

ABSTRACT

A readily releasable means for holding and operating an arbor construction of a type carrying a pulley and tool to be cyclically driven from an electric motor assembly includes a mounting base providing a seat to receive the motor. The motor can be rotatably positioned relative to the seat for proper positioning of the tool. The arbor rests in a readily releasable bearing block while means are provided to align the sheaves of the arbor pulley and a drive pulley mounted on the motor shaft so that the two sheaves lie in the same plane.

United States Patent Homer G. Allen 2726 Haste SL, Berkeley, Calif. 94704 7,509

Feb. 2, 1970 Aug. 3, 197 l lnventor Appl: No. Filed Patented QUICK CHANGE MOTOR-MOUNTED ARBOR MOUNTING ASSEMBLY AND REPLACEABLE UNIT THEREFOR 9 Claims, 3 Drawing Figs.

0.8. CI ..74 /242.l5 R,

5 H126 Int. Cl Fl6h 7/10, B24b 7/00 Field of Search 74/242.15 R; 5 1/126 [5 6 References Cited UNITED STATES PATENTS 2,517,328 8/1950 Lownsbery 74/242.l5 (R) 3,091,974 6/1963 Brill et al. 74/242.15 (R) 3,415,238 12/1968 Wagner ..7.4/242.l5 (R) X 3,430,507 3/1969 Hurst et al. 74/242.l5 (R) Primary Examiner- Leonard H. Gerin Anorney-Flehr, Hohbach, Test, Albritton & Herbert ABSTRACT: A readily releasable means for holding and operating an arbor construction of a type carrying a pulley and tool to be cyclically driven from an electric motor assembly includes a mounting base providing a seat to receive the motor. The motor can be rotatably positioned relative to the seat for proper positioning of the tool. The arbor rests in a readily releasable bearing block while means are provided to align the sheaves of the arbor pulley and a drive pulley mounted on the motor shaft so that the two sheaves lie in the same plane.

PATENTEU AUG 3m SHEET 2 BF 2 Fig. 2

INVENTOR. Homer 6. Allen m4 WW5,

QlUlliCllt CHANGE MOTOR-MOUNTED ARBOR MOUNTING AESIEMIEILI! AND IitElPlLAClEAlllllLlE lUNllll Tll-IIEllllEIFOlR BACKGROUND OF THE INVENTION This invention pertains to shop tools of a type employing a rotatable arbor arranged to carry a cyclically moving tool, such as a grinding or polishing wheel, wire brush, saw or the like.

It is believed to be a continuing objective of equipment of the above kind to seek ways in which to minimize the time and expense involved in substituting one tool for another.

As disclosed herein, an arbor mounting assembly is provided along with an interchangeable arbor unit adapted to operate in conjunction with any of a number of different cyclic tools, such as disc sanders, grinding wheels, rotary files, drum sanders, small circular saws, cutoff wheels, polishing wheels, wire brushes and the like. Thus, apparatus of the kind disclosed herein is highly versatile and is arranged for minimizing the time involved in substituting one tool for another with respect to a single motor.

In addition to the above general objectives, it is also believed a continuing objective of apparatus of the present type to seek to generally improve their function and performance by unobvious means whereby the relatively unskilled worker can utilize such equipment without need for extensive trainmg.

OBJECTS It is a general object of the present invention to provide an improved arbor mounting construction and replaceable arbor unit for cooperation therewith having the above and other advantages.

It is another object of the present invention whereby a motor-driven arbor assembly can be arranged so that the axis of rotation of the arbor can be moved in a circular path substantially concentrically about the axis of rotation of the drive shaft of an electric motor so that tension established in a drive belt trained between pulleys respectively located on the two shafts will not be varied by such movement positioning the arher.

It is another object of the present invention to provide an instantly releasable, interchangeable arbor unit arranged in such a manner whereby a number of inexpensive individual arbor units, each equipped with different tools, can be selectively interchanged one for the other without need for readjustment of tension in the cyclic drive belt.

A further object of the invention is to provide a compact unit occupying a minimum of space and having a simplified design of a type tending to provide low cost for replaceable parts and components.

The foregoing and other objects of the invention will become more readily apparent from the following description when considered in conjunction with the drawings herein.

SUMMARY OF THE INVENTION In general, there has been provided means for holding and operating an arbor construction of a type carrying a pulley and tool to be cyclically driven from an electric motor assembly. The mounting assembly comprises means forming a mounting construction adapted to be adjustably supported by the motor and carrying a bearing block adapted to receive an arbor assembly oriented in substantially spaced parallel relation to the shaft of the electric motor. A portion of the bearing block is readily movable to admit the arbor assembly thereto to be lodged therein in conjunction with clamping means for closing the movable block portion tightly about the assembly. Means for aligning the sheaves or grooves of the pulleys carried respectively on the drive shaft of the electric motor and the arbor element whereby the grooves will lie in a common plane adapted to support a drive belt trained about both pulleys is further provided along with adjustment means for moving one of the pulleys with respect to the other in order to vary tension in the belt. Preferably, the arbor assembly includes an arbor element and bearing portion of a generally cylindrical nature to be lodged in the bearing block carried by the mounting assembly. The base for the mounting assembly is arranged to be moved between advanced and retracted positions so as to tension the belt and to hold the tension in the tightened or loosened belt.

Further, a seat is formed to receive the generally cylindrical side of the casing or housing of a motor. Strap portions are disposed about the motor housing and each anchored at one end relative to the seat whereby fastening means at the other ends of the strap portions may be used for drawing the housing tightly to the seat. The fastening means is readily releasable to permit the motor housing to be rotated relative to its seat and about the axis of its drive shaft. The arbor mounting assembly is supported by the housing of the motor and adapted to support the rotatable arbor unit in spaced parallel relation to the axis of the drive shaft. by moving the mounting assembly, ten sion in the belt is varied.

The arbor is held in a quick release bearing block of the above type and includes a bearing portion disposed substantially midway between the ends of the arbor in a manner to be gripped in the bearing block. Annular means, such as a pulley, is secured to the arbor for rotation therewith and cooperates with cyclically driven means of a motor to rotate the arbor. The bearing portion includes registration means such as detent means disposed about the exterior of the bearing portion and serving to register the two pulleys in the plane of the cyclically driven belt when the bearing portion is carried properly in the bearing block. Each end of the arbor is arranged for readily attaching a cyclic tool. The opposite ends of the arbor element are threaded respectively with left and right hand threading.

ll-laving in mind the foregoing general description of the invention herein, a description of a preferred embodiment appears immediately below which is to be considered in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a front elevation view according to the invention;

FIG. 2 is a side elevation view of FIG. I, partially in section; and

FIG. 3 is an enlarged detail section view of FIG. 2 taken along the line 3-3 thereof with the closure portion 39 in its released condition.

DESCRIPTION OF THE PREFERRED EMBODIMENT An electric motor assembly 10 is shown in the drawing of a type having a drive shaft Ill mounting a drive pulley 12 thereon and further including an outer casing of a type comprised of a pair of end plates 13 attached to the opposite ends of a generally cylindrical casing portion M by means of a number of elongated bolts 16 which extend the length of motor assembly Ml. Thus, each of bolts 16 passes freely through an associated opening formed in one end plate 13 and is either screwed or fitted with a washer and nut at the opposite end of the motor assembly after extending through the other end plate 13.

Means are provided as a mounting seat such as the concave portion 117 formed in the base block 18. A pair of elongated flexible strap portions l9, II tightly hold motor assembly 10 in its seat 1l7. Each strap portion 19, 21 is suitably fixed to base block Id at one end and arranged to be bolted to a workbench or the like by means of the slotted tabs Ml formed at the end of strap portions 19, 211. The other ends of the strap portions 19, 211 are formed with an outwardly bent ear 22, 23 respectively. Ears 22, 23 are further formed in a manner whereby an elongated bolt 24l can be readily released so that the housing of motor assembly I'll can readily be rotated about the shaft llI after release of bolt 24. Thus, ear 23 includes a hole or other suitable perforation through which bolt 24 may be passed while car 22 includes an elongated slot 26. After releasing the nut 27, bolt 24 can be pivoted upwardly and thereby quickly removed from its retaining position within slot 26.

An arbor mounting assembly 28 comprises means forming a mounting construction adapted to be adjustably supported by motor assembly 10. Thus, the mounting construction includes a U-shaped cradle 36 having a pair of support arms 29 and a bearing block portion. Arms 29 are secured to an associated one of the two end plates 13 by means of one of the elongated plate-retaining motor bolts 16 or a similarly elongated bolt of a type adapted to employ a takeup nut 31 after passing through both arms 29. (Thus, in this instance, bolt 16 has been replaced by a similar bolt designated 16'.)

. Bolt 16' forms a pivot pin about which each of the cradle arms 29 may rotate. The degree of rotation of arms 29 is, however, limited by means of an elongated slot 32 formed in armate style in the lower end of arms 29 and arranged to be retained in frictional engagement with washer 33 held in place bynut 34, preferably a wing nut, carried upon bolt 16". The distance between the upper ends of cradle arms 29 is spanned by a mounting baseplate portion 36a upon which the arbor mounting assembly 28 is secured.

Assembly 28 is characterized, preferably, as a single casting including the arms 29 and plate portion 360, but could, of course, be assembled from component parts if desired.

Arbor mounting assembly 28 forms a bearing block for an arbor unit assembly 37 described further below.

Arbor mounting assembly 28 is suitably secured in fixed position upon baseplate portion 36a and comprises a lower support portion 38 and a closure portion 39 selectively movable to readily grip and release the arbor unit 37. Thus, it is readily apparent that closure portion 39 can be readily moved so as to admit arbor unit 37 thereto in a manner described below.

Means forming a readily releasable clamp 41 operates in a well known overcenter style whereby a bridle 41a is drawn by a thumb catch 41b tightly against and into a groove or recess formed in a fixed portion of the clamping assembly 41 as carried by closure portion 39.

The lower portion 38 of arbor mounting assembly 28 includes a registration rib 42 of an annular nature formed to protrude radially inwardly from the bearing surface 43 defined within the lower portion 38. Rib 42 cooperates with an annular registration groove 44 formed in the exterior surface of the outer race 46 of cylindrical bearing 47 carried on an arbor shaft 48 to form a portion of arbor assembly 37.

As will be explained further below, the function of the cooperation between the detent or registration means formed by rib 42 and groove 44 provides alignment of the grooves of sheaves 49, 51 or pulleys 52 and 12 whereby the two pulleys 52, 12 will lie in substantially the same plane. Pulley 52 rotates with arbor shaft 48 as will be described.

The closure portion 39 of arbor mounting assembly 28 is suitably arranged, such as by means of the hinge 53, so that it can be quickly moved away from the lower portion 38 so that arbor unit 37 can be merely tipped toward pulley 12 and thereby form sufficient slack in drive belt 54 to permit arbor unit 37 to be quickly and readily interchanged with another arbor unit similar to arbor unit 37.

Upon lodging the arbor unit 37 in the lower portion in registration with rib 42 by means of alignment of groove 44 therewith, closure portion 39 may be readily clamped down onto the cylindrical bearing portion 47 so as to hold the axis of rotation of arbor 37 in substantially parallel spaced relation with respect to the axis of rotation of drive shaft 1]. Accordingly, upon clamping a new arbor unit 37 properly in place, it will be apparent that the tension in the cyclically driven belt 54 will be the same as before (if it is assumed that the arbor pulley diameter is the same for each arbor).

Arbor 37 further includes a hollow cylindrical portion 56 telescopically pressed onto the end of the shaft 48. The hollow cylindrical portion 56 includes a projecting stub end 57 formed with threads for receiving a nut 58 so as to clamp a pair of washers 59, 61 tightly together to grip a cyclically driven tool 62 therebetween. For example, a typical tool may be a grinding wheel, small saw blade, etc.

Each end of arbor 37 provides similar clamping of a tool but with the exception that the threads on the opposite ends of arbor 37 are arranged whereby one end is threaded with righthand threads, and the other end threaded with left-hand threads in a manner whereby rotation of the arbor will, if anything, serve to tighten the nuts 58 against the washers 61 so as not to come loose during operation.

A pulley 52 is mounted in fixed relation on portion 56 by means of a setscrew 63.

Means are provided whereby the spacing between the axis of rotation of arbor shaft element 48 can be moved between retracted and advanced positions with respect to the axis of rotation of shaft 11. in this manner, the tension in belt 54 may be properly adjusted. Accordingly, the pivotal nature of the mounting of arms 29 permits the mounting baseplate portion 36a to be moved about the pivot point defined by the motor bolt 16.

A combination lever arm-carrying handle 64 includes positive adjustable spacer means to establish and hold the tension desired in belt 54 as a result of the movement of lever arm 64. Thus, a pair of threaded adjustment pins 66, 67 are carried in portions of lever arm 64 flanking the pivot point 16. Pins 66, 67 can be moved into contact with the motor casing and are each provided with locking means in the form of the locking nuts 68, 69. Thus, they may be locked in fixed relation to the casing or housing of motor assembly 10 to maintain the positioning of lever arm 64 fixed relative to the motor casing.

Accordingly, it will be readily apparent that in order to move the axis of rotation of arbor element 47 radially with respect to the axis of rotation of shaft 11, one pin, such as pin 67, will be slacked off after unlocking nuts 69, and pin 66 will be further extended toward motor assembly 10 (after unlocking the nuts 68). This action will continue until pin 67 contacts the casing surface of motor assembly 10. Upon contacting the casing of motor assembly 10, pin 67 will serve to arrest further change in the spacing between the two pulley axis of rotation.

if, at this time, a tool 62 is properly positioned relative to the work to be performed, no further adjustment may be necessary.

On the other hand, if it is necessary to raise or to lower the working edge of the cyclically driven tool 62, this may now be readily accomplished without effecting tension in belt 54 simply by unscrewing nut 27 to slack off straps 19, 21 which readily permits rotation of motor assembly 10 and also provides circular movement of the arbor shaft element 48. it will be readily apparent that the axis of rotation of arbor 37 traverses a circular path concentrically arranged about the axis of rotation of drive shaft 11. Thus, no change in the tension in drive belt 54 will occur and lever arm 64 can be employed at this time solely to properly locate the working edge or portion of the cyclically driven tool 62 relative to a workpiece. Upon arriving at the proper location, it is then a simple matter merely to tighten nut 27 to secure motor assembly 10 tightly in its proper orientation.

Finally, a suitable belt guard 71 is also arranged to follow the above concentric circular movements of the apparatus so as to retain belt 54 within a protective relationship to belt guard 71 for all positions of the arbor 37.

From the foregoing, it will be readily evident that arbor 37 is supported by the cylindrically formed bearing portion 47 located substantially at the arbor midpoint and that the drive pulley 52 is spaced very slightly to one side of the support bearing. Accordingly, very little wear or undue strain will be applied to the cylindrical bearing by virtue of pulley 52 being driven from the drive belt 54.

it is generally understood that it is advantageous to be able to drive an arbor assembly from substantially its midpoint but it is not ordinarily convenient or feasible. In the present arrangement, however, such favorable driving relationship has been provided so as to achieve the advantages of such a relationship.

From the foregoing, it will be further apparent that there has been provided an improved readily replaceable arbor unit in conjunction with a novel arbor mounting assembly whereby quick release of one arbor can be made in a manner to admit a second arbor unit, carrying a different work tool and be registered in a proper position in alignment with the drive pulley of a motor assembly whereby adjustment of the tension in the drive belt will not be necessary and wherein the tool can be readily positioned properly in conjunction with a workpiece.

lclaim:

1. For holding and operating an arbor construction carrying a pulley and a tool cyclically driven from an electric motor assembly of a type having a pulley adapted to rotate with the drive shaft of the motor, a mounting assembly comprising means forming a mounting construction adapted to be adjustably supported by the motor, a bearing block carried by said mounting construction and adapted to receive an arbor assembly therein to be carried in said block in substantially parallel relation to the motor shaft, said block including a portion readily movable to admit the arbor assembly to be lodged therein, means for closing said block portion to be clamped about said assembly, means for aligning the sheaves of said pulleys into a common plane adapted to support a drive belt trained about both of the pulleys, and adjustment means for moving one of said pulleys relative to the other to vary the tension in the belt.

2. For use with an electric motor of a type having a drive shaft and an outer casing forming a housing, the combination of a pulley on the motor drive shaft to rotate therewith, a mounting assembly for holding and operating an arbor construction, said mounting assembly comprising means forming an arbor mounting base supported upon the motor for adjustment between advanced and retracted positions with respect to the drive shaft of the motor, a bearing block assembly carried by said mounting base, an arbor assembly disposed in said block assembly in substantially parallel relation to the motor shaft, said arbor assembly including an arbor element and a bearing portion therearound to be lodged in said block, said block assembly including a portion readily movable to admit the arbor assembly thereto, means for closing saidportion about said bearing portion to hold said arbor in spaced substantially parallel relation to the axis of said motor shaft, an annular drive connection on the arbor for rotation therewith, a cyclic belt trained about both said drive connection and said pulley to rotate said arbor, means for moving said mounting base between said advanced and retracted positions to vary the tension in said belt and thereafter to hold said tension, and means on the arbor for carrying a cyclically moving tool to be driven by said motor.

3. For use with an electric motor of a type having a drive shaft, a pulley on the shaft to rotate therewith, and an outer casing around the motor forming a generally cylindrical housing, the combination of means forming a seat to receive a portion of the side of the motor housing therein, strap portions disposed about said housing and anchored relative to said seat at one end of each said portion, fastening means at the other ends of said portions for drawing said housing tightly to said seat, said fastening means being readily releasable to permit said motor housing to be rotated relative to said seat, an arbor mounting assembly carried by said housing disposed and adapted to support rotatable arbor means in spaced, substantially parallel relation to said drive shaft, means forming a driving connection between said pulley and adapted to engage and drive the arbor, means for moving said mounting assembly to vary said spaced relation and, upon release of said fastening means, for rotating said housing and mounting assembly while maintaining said spaced relation constant.

4. Arbor mounting apparatus according to claim 3 wherein said arbor mounting assembly includes a bearing block having a first portion adapted to receive an arbor bearin therein and a second portion selectively movable to grip an release said arbor means.

5. Arbor mounting apparatus according to claim 3 wherein the last said means includes a lever arm secured to said arbor mounting assembly, means forming a pivot support for said mounting assembly to permit said mounting assembly to move between advanced and retracted positions relative to said drive shaft, and positive adjustable spacer means cooperating with said lever arm on opposite sides of said pivot and serving to maintain the lever arm fixed relative to said motor casing, said spacer means serving to adjust the spacing between the axes of said drive shaft and said arbor, said driving connection including a belt, adjustment of said spacing serving to vary the tension in the belt, said lever arm serving, upon release of said fastening means, to be adapted to rotate the arbor and motor about said drive shaft while maintaining said spaced relation and tension constant.

6. Arbor mounting apparatus according to claim 5 wherein said casing includes end closure plates and said pivot comprises means holding an end closure plate securely to said motor.

7. An arbor assembly adapted to be held in a quick release bearing block said assembly comprising an arbor element, a bearing portion carried by said element between the ends of said element and adapted to engage said bearing block, means rotating with the arbor element and adapted to cooperate with cyclically driven means of a motor to rotate the arbor element, registration means serving to align the penultimate named means in the plane of said cyclically driven means when said bearing portion is carried in said block, and means carried by said arbor for readily attaching a cyclic tool.

8. An arbor assembly according to claim 7 wherein the last named means includes threaded ends of the arbor element, the opposite ends being threaded respectively with left-hand and right-hand threading.

9. An arbor assembly according to claim 7 wherein the registration means includes means forming a detent cooperating with a recess, said registration means: being formed between said bearing portion and said block. 

1. For holding and operating an arbor construction carrying a pulley and a tool cyclically driven from an electric motor assembly of a type having a pulley adapted to rotate with the drive shaft of the motor, a mounting assembly comprising means forming a mounting construction adapted to be adjustably supported by the motor, a bearing block carried by said mounting construction and adapted to receive an arbor assembly therein to be carried in said block in substantially parallel relation to the motor shaft, said block including a portion readily movable to admit the arbor assembly to be lodged therein, means for closing said block portion to be clamped about said assembly, means for aligning the sheaves of said pulleys into a common plane adapted to support a drive belt trained about both of the pulleys, and adjustment means for moving one of said pulleys relative to the other to vary the tension in the belt.
 2. For use with an electric motor of a type having a drive shaft and an outer casing forming a housing, the combination of a pulley on the motor drive shaft to rotate therewith, a mounting assembly for holding and operating an arbor construction, said mounting assembly comprising means forming an arbor mounting base supported upon the motor for adjustment between advanced and retracted positions with respect to the drive shaft of the motor, a bearing block assembly carried by said mounting base, an arbor assembly disposed in said block assembly in substantially parallel relation to the motor shaft, said arbor assembly including an arbor element and a bearing portion therearound to be lodged in said block, said block assembly including a portion readily movable to admit the arbor assembly thereto, means for closing said portion about said bearing portion to hold said arbor in spaced substantially parallel relation to the axis of said motor shaft, an annular drive connection on the arbor for rotation therewith, a cyclic belt trained about both said drive connection and said pulley to rotate said arbor, means for moving said mounting base between said advanced and retracted positions to vary the tension in said belt and thereafter to hold said tension, and means on the arbor for carrying a cyclically moving tool to be driven by said motor.
 3. For use with an electric motor of a type having a drive shaft, a pulley on the shaft to rotate therewith, and an outer casing around the motor forming a generally cylindrical housing, the combination of means forming a seat to receive a portion of the side of the motor housing therein, strap portions disposed about said housing and anchored relative to said seat at one end of each said portion, fastening means at the other ends of said portions for drawing said housing tightly to said seat, said fastening means being readily releasable to permit said motor housing to be rotated relative to said seat, an arbor mounting assembly carried by said housing disposed and adapted to support rotatable arbor means in spaced, substantially parallel relation to said drive shaft, means forming a driving connection between said pulley and adapted to engage and drive the arbor, means for moving said mounting assembly to vary said spaced relation and, upon release of said fastening means, for rotating said housing and mounting assembly while maintaining said spaced relation constant.
 4. Arbor mounting apparatus according to claim 3 wherein said arbor mounting assembly includes a bearing block having a first portion adapted to receive an arbor bearing therein and a second portion selectively movable to grip and release said arbor means.
 5. Arbor mounting apparatus according to claim 3 wherein the last said means includes a lever arm secured to said arbor mounting assembly, means forming a pivot support for said mounting assembly to permit said mounting assembly to move between advanced and retracted positions relative to said drive shaft, and positive adjustable spacer means cooperating with said lever arm on opposite sides of said pivot and serving to maintain the lever arm fixed relative to said motor casing, said spacer means serving to adjust the spacing between the axes of said drive shaft and said arbor, said driving connection including a belt, adjustment of said spacing serving to vary the tension in the belt, said lever arm serving, upon release of said fastening means, to be adapted to rotate the arbor and motor about said drive shaft while maintaining said spaced relation and tension constant.
 6. Arbor mounting apparatus according to claim 5 wherein said casing includes end closure plates and said pivot comprises means holding an end closure plate securely to said motor.
 7. An arbor assembly adapted to be held in a quick release bearing block said assembly comprising an arbor element, a bearing portion carried by said element between the ends of said element and adapted to engage said bearing block, means rotating with the arbor element and adapted to cooperate with cyclically driven means of a motor to rotate the arbor element, registration means serving to align the penultimate named means in the plane of said cyclically driven means when said bearing portion is carried in said block, and means carried by said arbor for readily attaching a cyclic tool.
 8. An arbor assembly according to claim 7 wherein the last named means includes threaded ends of the arbor element, the opposite ends being threaded respectively with left-hand and right-hand threading.
 9. An arbor assembly according to claim 7 wherein the registration means includes means forming a detent cooperating with a recess, said registration means being formed between said bearing portion and said block. 